WO1999039756A2

WO1999039756A2 - Supporting material for medicinal purposes

Info

Publication number: WO1999039756A2
Application number: PCT/EP1999/000738
Authority: WO
Inventors: Peter Himmelsbach; Marike Sinnen
Original assignee: Beiersdorf Ag
Priority date: 1998-02-06
Filing date: 1999-02-04
Publication date: 1999-08-12
Also published as: ES2185317T3; AU2521799A; WO1999039756A3; EP1053030A2; ATE226833T1; DE19804774A1; DE59903247D1; AU752378B2; EP1053030B1

Abstract

The invention relates to supporting material for medicinal purposes. The supporting material is characterized in that it is a non-woven material which is topstitched with sewing threads and which has a maximum tensile strength of at least 10 N/cm. In addition, the supporting material is partially or completely coated on at least one side with a doped adhesive material.

Description

description

Substrates for medical purposes

The invention relates to a carrier material for medical purposes, preferably a medical plaster, which is coated at least on one side over the entire surface or partially with a doped adhesive.

Numerous materials based on foils, woven fabrics, knitted fabrics, fleece, gel or foam are already known as carrier materials for medical purposes and are also used in practice. The materials, which are often still coated with a self-adhesive, must be compatible with the skin, generally permeable to air and water vapor, and be easy to mold and conform. Because of these requirements, a carrier that is as thin or soft as possible is often preferred. Sufficient strength and, if necessary, limited elasticity are also required for the handling and use of the carrier materials. Furthermore, the carrier material should have sufficient strength and low elasticity even after it has been soaked.

Thin supports, especially those made of nonwovens, are well permeable to air and water vapor. However, their strength is too low and their elongation too high for certain applications. Furthermore, the padding effect is not sufficient for these inexpensive carriers.

For special applications, for example rheumatic plasters, inelastic supports with high strength in the direction of stress are required. This is achieved by using woven or knitted fabrics, usually made of cotton or viscose. As a rule, such carrier materials with a correspondingly high basis weight are cost-intensive. A high degree of conformability and adaptability can only be achieved with fabrics with lower strength. However, these generally point then too little padding under stress, which is undesirable for the application.

In general, the bandages listed may lose strength or become more elastic when drenched. This is also undesirable for use and has so far been compensated for by a more frequent dressing change, which on the other hand is cost-intensive.

The AU 73555/74, for example, describes a carrier material reinforced with glass threads for medical foam-based applications.

US 4,668,563 describes a glass fiber reinforced material which is elastic. However, all of the carrier materials mentioned have not been reinforced by sewing.

DE 44 42 092 and DE G 94 01 037 describe adhesive tapes based on sewing fleece, which are partially coated on the back of the carrier. Such tapes are preferably used in cable banding. DE 44 42 093 is also based on the use of a nonwoven as a carrier for an adhesive tape, here a transverse fiber nonwoven reinforced by the formation of stitches from the fibers of the nonwoven is described.

DE 44 42 507 also discloses an adhesive tape for cable bandaging, but it is based on so-called Kunit or Multikunit fleece. However, the use or special suitability of these carrier materials for medical purposes cannot be derived from the documents mentioned. In particular, there is no indication in the publications of sufficient skin compatibility of the adhesives, of a functionally safe adhesion to the skin or of advantageous permeability to air and water vapor. Furthermore, doping with active substances is not mentioned.

No. 4,773,238 describes a longitudinally sewn-over fiber fleece, the sewing seams not to have more than 20% by weight, based on the weight of the entire fleece. The use according to the invention as an insert for filters in dust filtering is proposed. No. 4,967,740 generally discloses carrier materials for use in medical care, which are produced in a 1-step process. In this process, the carrier is impregnated with an elastomer and a release solution at the same time. In this way, the material can be presented on a roll without release paper. Doping with active substances not mentioned.

In a list of a large number of suitable carriers, over-sewn nonwovens are also mentioned, without giving the expert a hint as to how the fleece should be designed in concrete terms in order to meet the requirements imposed on a medical carrier.

Transdermal therapeutic systems (TTS) are dosage forms of medication that deliver one or more drugs to the skin at their application site over a defined period of time. A distinction is made between systemic and locally effective dosage forms.

In the case of dosage forms which have a systemic effect, the active ingredient gets into the bloodstream by diffusion through the skin and can work throughout the body. Dosage forms with a local effect, on the other hand, only act on the applied areas. The active ingredient remains in the skin or in the layers underneath.

Strongly adhesive plasters are usually coated over their entire surface with a rubber adhesive. These adhesives then allow secure bonding, for example in critical areas such as joints, over a period of several days. However, sticking such products to the skin shows clear skin irritation and mechanical stress on the skin after detachment. The glue can only be removed without pain without aids.

Other adhesives are based on acrylate systems or block copolymers.

The aforementioned adhesive compositions can be pressure-sensitive self-adhesive compositions, the compositions for processing being able to be present in a carrier matrix. Common organic or inorganic solvents or dispersants are understood as carrier matrix. Systems without a carrier matrix are called 100% systems and are also not unknown. They are processed in the elastic or thermoplastic state. A common processing method is the melt.

Such hotmelt adhesives have also been described in the prior art. They are based on natural or synthetic rubbers and / or other synthetic polymers.

An advantage of the 100% systems is that, in terms of process engineering, they remove the carrier matrix, i.e. the aid is avoided, which increases processing productivity and at the same time reduces machine and energy expenditure. In this way, remaining residues of the carrier matrix are reduced. This in turn favors the lowering of the allergenic potential.

Due to their high hardness, skin adhesion is problematic for such 100% systems.

It is also known to apply self-adhesive compositions of this type not only over the entire surface but also in the form of a grid point, for example by screen printing (DE-PS 42 37 252), the spots of adhesive also being able to be of different sizes and / or different distributions (EP-PS 353 972) or by Gravure printing of webs connected in the longitudinal and transverse directions (DE-PS 43 08 649).

The advantage of the grid-like application is that the adhesive materials are permeable to air and water vapor and, as a rule, are easily removable if the carrier material is appropriately porous.

A disadvantage of these products, however, lies in the fact that if the surface of the adhesive layer, which is impermeable per se, is too high, the permeability to air and water vapor decreases accordingly, the consumption of adhesive mass increases and the adhesive properties suffer if the surface area of the adhesive layer is poor, ie the product dissolves, especially with heavy, textile substrates, too light from the surface.

Numerous embodiments of active substance-containing plasters have been described in the prior art, some of which work according to the reservoir principle, in which Before the active ingredient is released, for example, via a membrane, sometimes also with a matrix system or with a more complicated multilayer structure.

It is also known that the adhesive of the patch can be used as the matrix containing the active ingredient. In addition to self-adhesive compositions applied from solution, hotmelt adhesives have also already been proposed for this, for example in EP-A 663 431, EP-A 452 034, EP-A 305 757, DE-OS 43 10 012, DE-OS 42 22 334 and DE- C 42 24 325. The active substances listed here, if they have been named, are systemically active. Use of the carrier according to the invention is not described.

Examples of active substance-containing plasters are the active substance plasters which promote blood circulation and belong to the group of locally active therapeutic systems. The use of such plasters is indicated for the treatment of rheumatic complaints, sciatica, lumbago, neck stiffness, shoulder-arm pain as well as muscle tension and strains, muscle soreness or muscle, joint and nerve pain in the area of the musculoskeletal system.

Capsaicin, Belladonna and nonivamide are known active ingredients of such plasters that have a local effect on the circulation. Because of their application to the musculoskeletal system, they usually have to stick very well. The patches are usually coated over their entire surface with a resin-rubber adhesive which contains the active ingredient.

Such plasters, which usually have to be applied over a large area, can occasionally lead to mechanical skin irritation in sensitive patients after detachment.

The disadvantage described also applies to plasters containing active substances that contain substances other than those mentioned.

For example, WO 94/02123 describes an active ingredient plaster based on pressure-sensitive hotmelt compositions which contains low-melting and / or highly volatile active ingredients in a concentration of 2.5% by weight to 25% by weight. The use of the carrier according to the invention is not described. EP 0 663 431 A2, EP 0 443 759 A3, EP 0 452 034 A2 and US 5,371, 128 describe uses of pressure-sensitive hotmelt pressure-sensitive adhesives on a silicone basis with various additives and in different designs. Use of the carrier according to the invention is not described.

DE 43 10 012 A1 describes the construction of a dermal therapeutic system from meltable poly (meth) acrylate mixtures.

In particular, the release of several active ingredients from polymer systems, which only one type of polymer seems difficult. Systems with several polymer types are critical in their compatibility. Use of the carrier according to the invention is not described.

DE 43 16 751 C1 describes a multi-chamber system for the administration of active substances. EP 0 439 180 describes an active ingredient patch for the administration of tulobuterol. EP 0 305 757 describes an active ingredient patch for the administration of nicotine. EP 0 305 758 describes an active ingredient patch for the administration of nitroglycerin. EP 0 305 756 describes an adhesive of substances and their production and use. Use of the carrier according to the invention is not described.

DE 37 43 945 describes an adhesive for dispensing substances and the manufacturing process. The described hotmelt adhesive based on SIS is not a self-adhesive device. The processing ranges specified there are significantly lower than those of hotmelt adhesives and would not provide sufficient anchoring of the adhesive for the systems described. Use of the carrier according to the invention is not described.

WO 96/22083 shows a polyisobutylene adhesive for transdermal purposes, which has a tackifier with a high glass transition point. Use of the carrier according to the invention is not described. JP 07-196505 describes an administration of inkomethacin in hotmelt PSAs. Here, a polyethylene foam is used as the carrier material. Use of the carrier according to the invention is not described.

The object of the invention was to provide a nonwoven-based carrier material which has been coated with a doped adhesive and is suitable for medical requirements and which, moreover, does not have the disadvantages known from the prior art.

This task is solved by a fleece as set out in the main claim. An alternative embodiment is the subject of the independent claim 2. The subclaims comprise advantageous variants of the subject of the invention.

Accordingly, a nonwoven fabric sewn by means of sewing threads is used as a backing material for medical purposes, the number of seams on the nonwoven fabric advantageously being at least 3 / cm, preferably 5 / cm to 50 / cm. The maximum tensile force of the carrier material amounts to at least 10 N / cm, preferably 20 to 450 N / cm, particularly preferably 30 to 250 N / cm, and the carrier material is coated at least on one side with a doped adhesive in whole or in part.

The sewing threads preferably have a water absorption of less than 30%, particularly preferably less than 20%. The water absorption can be regenerated by the air humidity.

Accordingly, polymeric fibers made of polypropylene, polyester, polyamide, aramid or polyethylene and also mineral fibers such as glass fibers or carbon fibers can advantageously be used as materials for the sewing threads. Threads or mixed twists, in particular siromix, can also be used. Mixed fiber threads, yarns or twists can also be used for special applications. Furthermore, the sewing threads can be at least partially colored in order to make the carrier material more visually appealing. The sewing thread can also be elastic for special applications. This then regenerates an elastic base support with an elongation of up to 250% at a load of 10 N / cm. For example, a polyamide thread (Lycra®, DuPont) may be mentioned here. Such a carrier material produces a compression force of 0.2 N / cm to 10 N / cm at an elongation of 20% to 70% and is used in compression technology.

In the alternative embodiment of the subject matter of the invention, a fleece is used as a carrier material for medical purposes. The fleece is reinforced by the formation of seams, which are formed by stitches from the fibers of the fleece, the number of seams on the fleece advantageously being at least 3 / cm, preferably 5 / cm to 50 / cm. The maximum tensile force of the backing material is at least 10 N / cm, preferably 20 to 450 N / cm, particularly preferably 50 to 250 N / cm, and the backing material is partially or fully coated on at least one side with a doped adhesive.

The carrier materials are based on known nonwovens, which are mechanically consolidated, by sewing on with separate threads or by stitching.

In the first case, the nonwoven thread sewing fabrics result. To produce this, a nonwoven fabric is presented, which can be cross-paneled, for example, and sewn on with separate threads in fringed or tricot layers.

These nonwovens are known under the name "Maliwatt" (from the Malimo company) or Arachne.

In the second type of consolidation, a cross-paneled fleece is preferably also presented. During the consolidation process, needles pull fibers out of the fleece itself and form them into stitches, with seams being created in fringe layers. This nonwoven knitted fabric is known under the name "Malivlies", also from the Malimo company.

An overview of the various types of mechanically consolidated nonwoven fabrics can be found in the article "Laminating Car Upholstery Fabrics with Nonwoven Fabrics" by G. Schmidt, Melliand Textile Reports 6/1992, pages 479 to 486. Advantageously, the nonwovens have longitudinal seams, the orientation of the sewing threads being oriented according to the stress on the carrier material in use.

All organic and inorganic fiber materials on a natural and synthetic basis can generally be used as starting materials for the nonwoven fabric. Examples include viscose, cotton, silk, polypropylene, polyester, polyurethane, polyamide, aramid or polyethylene, as well as mineral fibers such as glass fibers or carbon fibers. However, the present invention is not limited to the materials mentioned, but a large number of further fibers can be used for the formation of nonwovens.

The fibers used to form the fleece preferably have a water retention capacity of more than 0.5%, preferably between 2 to 70%, particularly preferably between 3 and 50%.

In a preferred embodiment, the carrier material has a maximum tensile force elongation of less than 40%, preferably less than 15%, particularly preferably less than 10%. For a nonwoven fabric sewn by means of sewing threads, this is achieved, on the one hand, by using a sewing thread material with a high modulus of elasticity, and, on the other hand, by using a sewing stitch which ensures that the sewing thread layer is as stretched as possible.

Advantageous material combinations are, for example, sewing threads made of high-strength polymer fibers such as polyamide, polyester, highly stretched polyethylene or mineral fibers such as glass and non-woven materials such as cotton or wool.

For a fleece in which the formation of seams occurs because the stitches are formed from the fibers of the fleece, the material of the fleece provided must be selected accordingly; the same applies to the sewing stitch.

It has also proven to be advantageous if the carrier material should have a weight per unit area of up to 500 g / m ² , preferably 10 to 350 g / m ² . In a further advantageous embodiment, the backing material can be torn by hand perpendicular to the orientation of the seams and / or in the direction of the seams. This is used when the carrier material according to the invention is wound onto a roll on itself.

In another embodiment, this tearability is not necessary. This can be pre-cut plasters.

Furthermore, the carrier material can be reinforced with one or more threads made of monofilament, multifilament, staple fiber yarn or spun fiber yarn and / or with oriented high-strength fibers, the threads and / or fibers in particular having a strength of at least 40 cNΛex. It is also possible to use twisted or mixed twisted yarns, in particular siromixed twins. Mixed fiber threads, yarns or twists can also be used for special applications. This can be, for example, wrapping yarns or special staple fiber wrapping yarns.

It is advantageous here that by combining different types of fibers, special or special properties can already be achieved in the reinforcing thread. Examples are the combinations of polyester or polyamide with cotton or rayon.

The reinforcing fibers or threads can consist of organic or inorganic materials, for example and preferably consist of glass, carbon, polyester or special polyamides. Furthermore, the reinforcing fibers can be at least partially colored in order to make the carrier material more visually appealing. In this way it is easily possible to differentiate the reinforced beams optically. Dyed glass or polymer threads are particularly suitable for this.

In an advantageous embodiment variant, the addition of high-strength fibers or threads with a maximum tensile force of more than 40 cN / tex shows a maximum tensile force of more than 50 N / cm and an elongation of less than 25% with a basis weight of less than 140 g / m ² . The number of threads or high-strength fibers attached or introduced depends primarily on the intended use and the desired maximum tensile force and elongation at maximum tensile strength of the carrier material, its own nature and the respective strength of the fibers and threads themselves and can therefore vary within relatively wide limits.

Advantageous material combinations are, for example, reinforcing threads or fibers made of high-strength polymer fibers such as polyamide, polyester, highly stretched polyethylene or mineral fibers such as glass and nonwoven materials such as cotton or cellulose.

Furthermore, the reinforcements are preferably inserted in a targeted manner in accordance with the direction of stress of the carrier material, i.e. longitudinal. However, if this is more expedient, they can also run additionally or only in the transverse or oblique direction or, for example, in a curved, spiral or zigzag shape or randomly.

In a further advantageous embodiment, the carrier material can be torn by hand perpendicular to the orientation of the reinforcement and / or in the direction of the reinforcement.

With higher strength of the nonwoven material and an increasing proportion of reinforcing fibers, the wearer can withstand greater stress and strain. Even very strongly reinforced carrier materials are able to absorb or let through large amounts of moisture and thus exert a pleasant user experience, with the reinforcements absorbing only a small amount of moisture, which means that their properties do not change.

Different active substances can preferably be contained in the adhesive, the amount of the active substance or active substances in the adhesive preferably being between 0.01 and approximately 60% by weight, preferably 0.1 to 20% by weight.

The term “active ingredients” in connection with the present invention includes chemical elements, organic and inorganic compounds that migrate out of the constituents of a generic adhesive containing them can and thereby produce a desired effect, understood. Human and veterinary medicine are of particular importance among the fields of application of the adhesive according to the invention, an embodiment of the invention in plaster form being particularly preferred here. Typical substances that can be administered via devices manufactured according to the invention are:

Aceclidine, amfetaminil, amfetamine, amyl nitrite, apophedrine, atebrin, alpostadil, azulene, arecoline, anethole, amylene hydrate, acetylcholine, acridine, adenosine triphosphoric acid, L-malic acid, alimemazine, allithiamine, azophyllate, ethynol isocyanin alginolamine, ethynol isothiocyanin , benzoyl peroxide, benzyl alcohol, bisabolol, Bisnore- phedrin, Butacetoluid, benactyzine, camphor, colecalciferol, chloral hydrate, clemastine, chlorobutanol, capsaicin, cyclopentamine, clobutinol, chamazulene, dimethocaine, codeine, chloropromazine, quinine, chlorothymol, cyclophosphamide, cinchocaine, Chloram- buzil , Chlorphenesin, diethylethane, divinylethane, dexchlorpheniramine, dinoprostone, dixyrazine, ephedrine, ethosuximide, enallyipropymal, emylcamate, erytrol tetranitrate, eme- tin, enflurane, eucalyptol, etofenamate, ethylmorphine, halofanamidine, fentanylamine, fentanylamine, fentanylamine, fentanylamine, fentanylamine, fentanylamine, fentanylamine, fentanylamine, fentanylamine, fentanylamine, fentanylamine, fentanyl amine carbohydrate , Hexylresorcinol, isoaminil citrate, isosorbide dinitrate, ibuprofen, iodine, iodoform, isoaminil, L idocaine, lopirine, levamisole, methadone, methyprylon, methylphenidate, mephenesin, methylephedrine, meclastin, methopromazine, mesuximide, nicethamide, norpseudoephedrine, menthol, methoxyflurane, methylpentinol, metixen, mesoprostol, oxytetracoline, oxyphenyloline, oxyphenolinol, oxyphenolinol, oxyphenolinol, oxyphenolinol, oxyphenolinol, oxyphenylol, proline Piperazine, pivazide, phensuximid, procain, phenindamine, promethazine, pentetrazole, profenamine, perazine, phenol, pethidine, pilocarpine, prenylamine, phenoxybenzamine, resoquin, scopolamine, salicylic acid ester, spartein, trichlorethylene, timolol, trifluperazine, tetracliprine, tetracliprine, tetra Tranylcypromine, trimethadione, tybamate, thymol, thioridazine, valproic acid, verapamil, and other active ingredients which are familiar to the person skilled in the art and can be absorbed through the skin, including mucous membranes. Of course, this list is not exhaustive.

The active ingredients are preferably distributed in the adhesive in commercially available homogenizers such as mixers, kneaders, rolling mills or screw systems. The active ingredient can be added to the completely prepared adhesive. For example, the active ingredient can also be incorporated into an intermediate stage or into the starting mixture. Self-adhesive compositions based on natural and synthetic rubbers and other synthetic polymers such as acrylates, methacrylates, polyurethanes, polyolefins, polyvinyl derivatives, polyesters or silicones with appropriate additives such as adhesive resins, plasticizers, stabilizers and other auxiliaries can be used as adhesive compositions, if necessary.

The adhesive composition can furthermore contain polymers which form a physically or chemically crosslinked gel.

Thermoplastic hot melt adhesives in particular have advantageous properties and are favored for production reasons.

their softening point should be higher than 50 ° C, since the application temperature for the coating is generally at least 90 ° C, preferably between 120 ° C and 150 ° C or 180 ° C and 220 ° C for special adhesives such as silicones. Post-crosslinking by high-energy radiation such as UV or electron beams may be appropriate.

Preferred hotmelt adhesives based on block copolymers are distinguished by their wide range of possible variations, because the required functional bonding to the skin is also achieved by the targeted lowering of the glass transition temperature of the self-adhesive composition as a result of the selection of the tackifiers, the plasticizers and the polymer molecule size and the molecular distribution of the insert components guaranteed at critical points of the human musculoskeletal system.

The high shear strength of the hot melt adhesive is achieved through the high cohesiveness of the polymer. The good grip tack results from the range of tackifiers and plasticizers used.

For particularly strong adhesive systems, the hotmelt adhesive is preferably based on block copolymers, in particular AB, ABA block copolymers or mixtures thereof. The hard phase A is primarily polystyrene or its derivatives, and the soft phase B contains ethylene, propylene, butylene, butadiene, isoprene or mixtures thereof, particularly preferably ethylene and butylene or mixtures thereof.

Polystyrene blocks can, however, also be present in the soft phase B, namely up to 20% by weight. However, the total styrene content should always be less than 35% by weight. Styrene fractions between 5% and 30% are preferred, since a lower styrene fraction makes the adhesive more supple.

In particular, the targeted blending of di-block and tri-block copolymers is advantageous, a proportion of di-block copolymers of less than 80% by weight being preferred.

In an advantageous embodiment, the hot-melt adhesive has the following composition:

10% to 90% by weight block copolymers,

5% to 80% by weight of tackifiers such as oils, waxes, resins and / or mixtures thereof, preferably mixtures of resins and oils, less than 60% by weight of plasticizer, less than 15% by weight of additives, less than 5% by weight of stabilizers, less than 60% by weight of active ingredient

The aliphatic or aromatic oils, waxes and resins used as tackifiers are preferably hydrocarbon oils, waxes and resins, the oils, such as paraffinic hydrocarbon oils, or the waxes, such as paraffinic hydrocarbon waxes, having a favorable effect on the skin adhesion due to their consistency. Medium or long chain fatty acids and / or their esters are used as plasticizers. These additives serve to adjust the adhesive properties and the stability. If necessary, further stabilizers and other auxiliaries are used.

It is possible to fill the adhesive with mineral or organic fillers, fibers, hollow or solid microbeads. The self-adhesive has a softening point above 70 ° C., preferably 80 ° C. to 140 ° C.

The hotmelt self-adhesive compositions are preferably set so that they have a dynamic-complex glass transition temperature of less than 15 ° C., preferably from 3 ° C. to -30 ° C., very particularly preferably from -3 ° C., at a frequency of 0.1 rad / s down to - 25 ° C.

In particular, high demands are made on the adhesive properties of medical backing materials. For an ideal application, the hot melt adhesive should have a high tack. The functionally adapted adhesive strength on the skin and on the back of the carrier should be present. Furthermore, so that there is no slipping, a high shear strength of the hot-melt adhesive is necessary.

Through the targeted lowering of the glass transition temperature of the adhesive as a result of the selection of the tackifier, the plasticizer as well as the polymer molecule size and the molecular distribution of the insert components, the necessary functional bonding with the skin and the back of the carrier is achieved. The high shear strength of the adhesive used here is achieved through the high coherency of the block copolymer. The good tackiness results from the range of tackifiers and plasticizers used.

The product properties such as stickiness, glass transition temperature and shear stability can be quantified well with the help of a dynamic mechanical frequency measurement. Here a shear stress controlled rheometer is used. The results of this measurement method provide information about the physical properties of a substance by taking the viscoelastic component into account. Here, at a given temperature, the self-adhesive composition is set in vibration between two plane-parallel plates with variable frequencies and low deformation (linear viscoelastic area). The quotient (Q = tan δ) between the loss module (G "viscous part) and the storage module (G 'elastic part) is determined with computer-aided control.

Q = tan δ = G'VG ' A high frequency is chosen for the subjective feeling of tackiness (tack) and a low frequency for the shear strength.

A high numerical value means better grip and poorer shear stability.

The glass transition temperature is the temperature at which amorphous or semi-crystalline polymers change from the liquid or rubber-elastic state to the hard-elastic or glassy state or vice versa (Römpp Chemie-Lexikon, 9th edition, volume 2, page 1587, Georg Thieme Verlag Stuttgart - New York , 1990). It corresponds to the maximum of the temperature function at a given frequency.

A relatively low glass transition point is particularly necessary for medical applications.

Self-adhesive compositions in which the ratio of the viscous component to the elastic component at a frequency of 100 rad / s at 25 ° C. is greater than 0.7 are preferred, or self-adhesive compositions in which the ratio of the viscous component to the elastic component at a frequency of 0.1 rad / s at 25 ° C is less than 0.4, preferably between 0.35 and 0.02, very particularly preferably between 0.3 and 0.1.

It is also particularly advantageous for use in medical products if the adhesive is partially applied to the backing material, for example by screen printing, screen printing, thermoflexo printing or gravure printing, because backing materials with a full line of adhesive can cause mechanical skin irritation under unfavorable conditions when applied and are in generally not permeable to air and water vapor. The application is preferred in the form of polygeometric domes and very particularly of domes in which the ratio of diameter to height is less than 5: 1. Furthermore, other shapes and patterns can also be printed on the carrier material, for example a printed image in the form of alphanumeric character combinations or patterns such as grids, stripes and zigzag lines.

The adhesive can be evenly distributed on the backing material, but it can also be applied in different thicknesses or densities over the surface in a manner that is functional for the product.

The principle of thermal screen printing is the use of a rotating, heated, seamless, drum-shaped perforated round stencil, which is fed with the preferred hot melt self-adhesive via a nozzle. A specially shaped nozzle lip (round or square squeegee) presses the hot-melt adhesive fed through a channel through the perforation of the stencil wall onto the carrier web. This is guided against the outer jacket of the heated sieve drum at a speed which corresponds to the speed of rotation of the rotating sieve drum.

The small adhesive spheres are formed according to the following mechanism:

The nozzle doctor blade pressure conveys the hot melt adhesive through the perforated screen to the carrier material. The size of the spherical caps is determined by the diameter of the sieve hole. The sieve is lifted off the carrier in accordance with the transport speed of the carrier web (rotational speed of the sieve drum). Due to the high adhesion of the adhesive and the internal cohesion of the hotmelt, the limited supply of hotmelt adhesive in the holes is subtracted from the base of the calottes already adhering to the contour, or is conveyed onto the carrier by the squeegee pressure.

At the end of this transport, depending on the rheology of the hot melt adhesive, the more or less strongly curved surface of the spherical cap forms over the predetermined base area. The ratio of the height to the base of the calotte depends on the ratio of the hole diameter to the wall thickness of the sieve drum and the physical properties (flow behavior, surface tension and wetting angle on the backing material) of the self-adhesive.

In the screen stencil in thermal screen printing, the web / hole ratio can be less than 3: 1, preferably less than or equal to 1: 1, in particular equal to 1: 3.

The described mechanism of formation of the calottes preferably requires absorbent or at least wettable carrier materials that can be wetted by hot-melt adhesive. Non-wetting support surfaces must be pretreated using chemical or physical processes. This can be done by additional measures such as corona discharge or coating with substances that improve wetting.

The size and shape of the domes can be defined in a defined manner using the printing process shown. The adhesive strength values relevant for the application, which determine the quality of the products produced, are within very narrow tolerances when properly coated. The base diameter of the spherical caps can be selected from 10 μm to 5000 μm, the height of the spherical caps from 20 μm to approx. 2000 μm, preferably 50 μm to 1000 μm, the range of small diameters for smooth supports, that of a larger diameter and larger spherical cap height is intended for rough or highly porous substrates.

The positioning of the domes on the carrier is defined by the geometry of the application, which can be varied within wide limits, for example engraving or screen geometry. With the help of the parameters shown, the desired property profile of the coating can be set very precisely, adjusted to the different carrier materials and applications.

The carrier material is preferably coated at a speed of greater than 2 m / min, preferably 20 to 200 m / min, the coating temperature being chosen to be greater than the softening temperature.

The self-adhesive composition can be applied to the backing material with a weight per unit area of greater than 15 g / m ² , preferably between 90 g / m ² and 500 g / m ² , very particularly preferably between 130 g / m ² and 500 g / m ² . The percentage of the surface coated with the self-adhesive composition should be at least 20% and can range up to approximately 95%, for special products preferably 40% to 60% and 70% to 95%. This can optionally be achieved by multiple application, it also being possible, where appropriate, to use self-adhesive compositions with different properties.

The combination of the preferred hot melt adhesive and the preferred partial coating ensures, on the one hand, that the medical product adheres securely to the skin, on the other hand, at least visually recognizable allergic or mechanical skin irritations are ruled out, even in the case of an application which spans several Days.

The depilation of the corresponding body regions and the mass transfer to the skin are negligible due to the high cohesiveness of the adhesive, because the adhesive is not anchored to the skin and hair, rather the anchoring of the adhesive to the carrier material is up to 12 N / cm (sample width) good for medical applications.

Due to the formed predetermined breaking points in the coating, skin layers are no longer shifted with or against each other when detached. The non-shifting of the skin layers and the reduced epilation lead to an unprecedented degree of freedom from pain with such strongly adhesive systems. Furthermore, the individual biomechanical adhesive force control, which has a demonstrable reduction in the adhesive force of these plasters, supports the detachability. The applied carrier material shows good proprioreceptive effects.

Depending on the carrier material and its temperature sensitivity, the hot melt adhesive can be applied directly or first applied to an auxiliary carrier and then transferred to the final carrier.

Subsequent calendering of the coated product and / or pretreatment of the carrier, such as corona radiation, for better anchoring of the adhesive layer can also be advantageous.

Furthermore, treatment of the hotmelt adhesive with electron beam postcrosslinking or UV radiation can lead to an improvement in the desired properties. In a further advantageous embodiment, the self-adhesive compositions are foamed before they are applied to the backing material.

The self-adhesive compositions are preferably foamed with inert gases such as nitrogen, carbon dioxide, noble gases, hydrocarbons or air or mixtures thereof. In some cases, foaming through thermal decomposition of gas-evolving substances such as azo, carbonate and hydrazide compounds has also proven to be suitable.

The degree of foaming, i.e. the gas content should be at least about 5% by volume and can range up to about 85% by volume. In practice, values from 10% by volume to 75% by volume, preferably 50% by volume, have proven successful. If you work at relatively high temperatures of around 100 ° C and a comparatively high internal pressure, very open-pored layers of adhesive foam are created that are particularly well permeable to air and water vapor.

The advantageous properties of the foamed self-adhesive coatings such as low adhesive consumption, high tack and good conformability even on uneven surfaces due to the elasticity and plasticity as well as the Initiaitack can be used particularly well in the field of medical products.

The use of breathable coatings in conjunction with elastic and breathable backing materials results in comfort that is subjectively pleasant to the user.

A particularly suitable method for producing the foamed self-adhesive works according to the foam mix system. Here, the thermoplastic self-adhesive under high pressure at a temperature above the softening point (about 120 ° C) with the gases provided, such as nitrogen, air or carbon dioxide in different volume fractions (about 10 vol .-% to 80 vol .-%) in implemented a stator / rotor system.

While the gas admission pressure is greater than 100 bar, the mixed pressures gas / thermoplastic in the system are 40 to 100 bar, preferably 40 to 70 bar. The PSA foam produced in this way can then reach the application plant via a line. Commercial nozzles, extruder or chamber systems are used in the application. Due to the foaming of the self-adhesive and the resulting open pores in the mass, the products coated with the adhesive are well permeable to water vapor and air when using a porous carrier. The amount of adhesive required is significantly reduced without impairing the adhesive properties. The adhesives have a surprisingly high tack because there is more volume per gram of mass and thus the adhesive surface available for wetting the surface to be adhered and the plasticity of the adhesives is increased by the foam structure. This also improves anchorage on the carrier material. In addition, as already mentioned above, the foamed adhesive coating gives the products a soft and supple feel.

Foaming also generally lowers the viscosity of the adhesive. As a result, the melting energy is reduced and thermally unstable carrier materials can also be coated directly.

The carrier material coated with the adhesive can have an air permeability of greater than 1

preferably greater than 15

very particularly preferably greater than 70 cm ^ cm ^ s), furthermore have a water vapor permeability of greater than 500 g / (m ² * 24h), preferably greater than 1000 g / (m ² * 24h), very particularly preferably greater than 2000 g / ( m ^* 24h).

In addition, the carrier material can also be provided with other equipment or treatments. These include, for example, corona, flame or plasma pretreatments to increase the anchoring of the self-adhesive on the base fleece. Calendering the backing material or the nonwoven not yet equipped with self-adhesive is also an advantageous treatment for the purpose of further strengthening or improving the anchoring of the self-adhesive.

Furthermore, the backing material on the side opposite to the side coated with self-adhesive composition can be equipped with a water-repellent layer or impregnation, which enables rapid wetting upon contact with water or Prevents sweat. In addition to the known impregnations, this can also be done by sewing on a film, advantageously a water vapor permeable film, directly when the nonwoven is solidified by sewing threads.

The backing material can also be equipped with a release layer or impregnation and / or varnish that reduces the adhesive strength of the self-adhesive composition. Here too, in addition to the known release materials, a film, advantageously a water vapor permeable film, can be sewn on directly when the nonwoven is consolidated.

The lamination of the nonwoven backing with at least one additional layer of foams or foils has also turned out to be advantageous, since this results in a combination of special properties. A foam has a much higher damping property than a non-laminated carrier. For example, films can be used to seal the surface.

In addition, the carrier material can be vaporized with metallic substances.

Finally, after the coating process, the carrier material can be covered with an adhesive-repellent carrier material, such as siliconized paper, or provided with a wound dressing or padding.

It is particularly advantageous that the carrier material is sterilizable, preferably γ- (gamma) sterilizable. For example, hot melt adhesives based on block copolymers that do not contain double bonds are particularly suitable for subsequent sterilization. This applies in particular to styrene-butylene-ethylene-styrene block copolymers or styrene-butylene-styrene block copolymers. There are no significant changes in the adhesive properties for the application.

The carrier material according to the invention has an adhesive force on the back of the carrier of at least 0.5 N / cm, in particular an adhesive force between 2.5 N / cm and 5 N / cm. Higher adhesive strengths can be achieved on other substrates.

It has been shown to be advantageous that such an adhesive-coated, reinforced carrier material during wetting, as is inevitable, for example, in water sports activities is, has improved stability compared to the commercially available carrier materials. The relative increase in the maximum tensile force elongation of self-adhesive carrier materials according to the invention after wetting is only half as large as that of commercially available self-adhesive carrier materials.

As a result, the carrier materials according to the invention, which are thus essentially inelastic, can be used for special medical purposes, and carrier materials whose use has hitherto failed due to insufficient strength and / or excessive elongation can also be used.

Backing materials based on woven, knitted, non-woven or composite products can preferably be used, provided that they otherwise meet the requirements for medical use.

example 1

A preferred carrier material is described below by way of example, without wishing to restrict the invention unnecessarily.

A non-woven fabric based on viscose was used as the carrier material. The nonwoven fabric was sewn over with a polyester thread, the number of sewing threads being 22 / cm sample width. The water absorption of the polyester thread was 0.3%. The carrier material was calendered and impregnated.

The carrier material thus produced had a maximum tensile force of 50 N / cm in the longitudinal direction and a maximum tensile force elongation of 28%. The weight per unit area was 120 g / cm ² . Complete wetting of the backing material was not possible due to the selection of the reinforcement materials. The carrier material has a thickness of 1.0 mm when unloaded, which produces a good cushioning effect.

The carrier material had an air permeability of 100 cnrVfcn ^ s) and water vapor permeability of more than 2500 g / (m ^{2 *} 24h) and could be torn and torn by hand in the transverse and longitudinal directions.

The hot melt adhesive was applied to the backing using thermal screen printing. The hot melt adhesive composition was as follows:

an A-B / A-B-A block copolymer consisting of hard and soft segments with a ratio of A-B-A to A-B of 2: 1 and a styrene content in the polymer of 13 mol%; the proportion of the adhesive is 40% by weight (Kraton G), a paraffin hydrocarbon wax with a proportion of the adhesive of 51% by weight,

Hydrocarbon resins with a share of 7.5% by weight (Super Resin HC 140), an anti-aging agent with a share of less than 0.5% by weight (Irganox). a hyperemic active ingredient (nonanonyl vanillylamid); 1% share. The components used were homogenized in a thermal mixer at 125 ° C. The glass transition was -9 ° C according to the above method.

Direct coating was carried out at 50 m / min at a temperature of 120 ° C. The carrier material was partially coated with 120 g / m ² , a 14 mesh screen template with a screen thickness of 300 μm being used.

The bandage produced by this method showed a reversible detachment from the skin and a good air and water vapor permeability. No skin irritation and negligible epilation after removal of the bandage were observed.

The carrier material thus produced shows good release of the active ingredient.

Example 2

A non-woven fabric based on viscose was used as the carrier material. The nonwoven fabric was sewn over with a polyamide thread, the number of sewing threads being 7 / cm sample width. The carrier material was calendered and impregnated.

The carrier material produced in this way had a maximum tensile force of 12 N / cm in the longitudinal direction and a maximum tensile force elongation of 28%. The weight per unit area was 140 g / cm ² . Complete wetting of the backing material was not possible due to the selection of the reinforcement materials. The carrier material has an unloaded thickness of 1.2 mm, which creates a good cushioning effect.

The carrier material had an air permeability core of 80

and water vapor permeability of more than 2500 g / (m ² * 24h) and could be torn and torn by hand in the transverse and longitudinal directions.

This hotmelt PSA was composed as follows: a SEPS block copolymer consisting of hard and soft segments and a styrene content in the polymer of 13 mol%; the proportion of the adhesive is 15% by weight (Kuraray Co.) a paraffin hydrocarbon resin with a proportion of 44% by weight of the adhesive, an anti-aging agent with a proportion of less than 1.0% by weight (Irganox

1010 Ciba)

Salicylic acid with a share of 40%

The adhesive components used were homogenized in a thermal mixer at 185 ° C 3.5. The active ingredient was added in the cooling phase at 120 ° C. and homogenized in the mixer for a further 130 min.

The softening point of this adhesive was approximately 85 ° C. (DIN 52011), and the adhesive showed a viscosity of 2100 mPas at 150 ° C. (DIN 53018, Brookfield DV II, column 21). According to the above, the glass transition was Method - 10 ° C.

The self-adhesive was applied to the entire surface with a nozzle. The direct coating was carried out at 50 m min at a temperature of 120 ° C. The carrier material was coated with 170 g / m ² .

The plaster material produced in this way shows a comparably good release of the active ingredient.

Claims

claims

1. backing material for medical purposes, characterized in that the backing material is a nonwoven fabric sewn by means of sewing threads with a maximum tensile force of at least 10 N / cm and that the backing material is coated at least on one side with a doped adhesive mass or partially.

2. Backing material for medical purposes, characterized in that the backing material is a non-woven fabric, which is formed by the formation of seams made from stitches

Fibers of the nonwoven are formed, reinforced, the maximum tensile force of the backing material being at least 10 N / cm and that the backing material is coated at least on one side with a doped self-adhesive mass or partially.

3. Backing material for medical purposes according to claim 1 or 2, characterized in that the number of seams, in particular longitudinal seams, on the fleece is at least 3 / cm, preferably 5 to 50 / cm.

4. carrier material for medical purposes according to claim 4, characterized in that the carrier material generates a compression force of 0.2 N / cm to 10 N / cm at an elongation of 20% to 70%.

5. carrier material for medical purposes according to claim 1 or 2, characterized in that the carrier material has a basis weight of up to 500 g / m ² , preferably 10 to 350 g / m ² .

6. carrier material for medical purposes according to claim 1 or 2, characterized in that the carrier material is reinforced with a thread or several threads of monofilament, multifilament, staple fiber yarn or spun yarn and / or with oriented high-strength fibers, the threads and / or Fibers in particular have a strength of at least 40 cN / tex.

7. backing material for medical purposes according to claim 7, characterized in that the backing material by hand perpendicular to the orientation of the seams and / or in Direction of the seams and / or perpendicular to the orientation of the reinforcement and / or in the direction of the reinforcement is tearable.

8. backing material for medical purposes according to at least one of the preceding claims, characterized in that the adhesive composition or the releasable active ingredients in an amount of 0.01 to 60 wt .-%, preferably from 0.1 to 20 wt .-% %, contains.

9. backing material for medical purposes according to at least one of the preceding claims, characterized in that the adhesive is a hot melt adhesive.

10. Carrier material for medical purposes according to at least one of the preceding claims, characterized in that the adhesive at a frequency of 0.1 rad / s has a dynamic-complex glass transition temperature of less than

15 ° C, preferably from 3 ° C to -30 ° C, very particularly preferably from -3 ° C to - 25 ° C.

11. backing material for medical purposes according to at least one of the preceding claims, characterized in that the adhesive has been foamed.

12. carrier material for medical purposes according to at least one of the preceding claim, characterized in that the adhesive is partially applied to the carrier material, in particular by screen printing, thermal screen printing, thermoflexo printing or gravure printing.

13. carrier material for medical purposes according to at least one of the preceding claim, characterized in that the adhesive is sprayed on.

14. backing material for medical purposes according to at least one of the preceding claim, characterized in that the adhesive is brought in the form of polygeometric domes on the backing material.

15. backing material for medical purposes according to at least one of the preceding claims, characterized in that the adhesive with a surface weight of greater than 15 g / m ² , preferably between 90 g / m ² and 500 g / m ² , very particularly preferably between 130 g / m ² and 500 g / m ² , on which carrier material is applied.

16. backing material for medical purposes according to at least one of the preceding claims, characterized in that the adhesive is sterilizable, preferably γ (gamma) sterilizable.

17. Backing material for medical purposes according to one or more of the preceding claims, characterized in that the backing material on the side opposite the side coated with the self-adhesive composition is equipped with a water-repellent layer, impregnation, release layer and / or coating.

Iδ.Material for medical purposes according to one or more of the preceding claims, characterized in that at least one additional layer of film, foams or nonwovens is applied to the carrier material.

19. Carrier material for medical purposes according to one or more of the preceding claims, characterized in that the carrier material has been vapor-coated with metallic substances.

20. carrier material for medical purposes according to one or more of the preceding claims, characterized in that the coated carrier material is covered after the application of the self-adhesive or provided with a wound dressing or padding.